This proposal seeks to test the efficacy of sleep-directed hypnosis as a complement to an existing empirically supported psychosocial intervention, Cognitive Processing Therapy (CPT) in sample of female survivors of interpersonal violence suffering from PTSD. Further, this proposal seeks to identify mechanisms of action in the therapy that lead to symptom modification, improvement in larger domains of functioning, and health-related concerns. Towards this end, a multi-method, multimodal assessment will be administered including daily and intermittent monitoring across psychiatric, psychological, and psychophysiological domains. Specifically, forty subjects will be randomly assigned to either a hypnosis + CPT (hypCPT) condition or to a symptom monitoring (3 weeks of monitoring to control for the passage of time and any potential effects of symptom monitoring) plus CPTactive control group (CPTac). Participants in this study will be administered a battery of interviews and self-report measures including the 1.) Clinician Administered PTSD Scale, 2.) Structured Clinical Interview for DSM-IV Axis I Disorders, 3.) Standardized Trauma Interview, 4.) PTSD Diagnostic Scale, 5) Beck Depression Inventory - II, 6.) Pennebaker Inventory of Limbic Landuigness, 7.) The SF-36 Health Survey, 8.) Quality of Life Inventory, 9.) Social Adjustment Scale, 10) Pittsburgh Sleep Quality Index, and the 11) Insomnia Severity Index. In addition, physiological indices will be used to assess the relationship between sleep impairment and hyperarousal as well as changes over time in physiological reactivity. A Psychomotor Vigilance Task will also be administered to test for the presence of sleep deprivation (i.e. "sleepiness" as measured by reaction time) as well as related changes over time. Subjects will monitor symptoms and daily stressors through the use of daily diaries as well as undergo formal assessments at pre-treatment, post- treatment and three month follow-up points. Conducting the proposed study will have important implications on remediating sleep impairment (the most often reported symptom of PTSD and one of the most refractory to treatment) utilizing a novel approach, the addition of hypnosis, within a traumatized population. Concurrently this proposal aims to illuminate the mechanisms of action in hypnosis, an understudied complementary treatment element with virtually no empirical support in the trauma literature.